I've constantly noticed when a girl moves from Ginza, her service levels drop significantly. Then continues to drop more as she moves to other shops

Seen J Ramu as well by the way. Her service levels weren't "S or A" Tier level to start off with anyway.

So bottom line, when a girl moves from Ginza, proceed with caution.

There are exceptions though. I mean, girls like K Hanna still maintained her high level of service even though she moved.